389a07672e9c  iOS: Automatic Password Fixes sometimes stall or time out after the device is locked

Classified as not security-relevant.
Triage note: Adds startForcedDisplayRefreshWindow/_forcedRefreshTimerFired and a presentationUpdateTimeout for backgroundTextExtractionEnabled; new feature plumbing. The NSTimer teardown in -invalidate is leak-prevention for the new code, not a fix to an existing bug.
This commit was flagged by the signal scorer and reviewed by AI (not a human). It is listed only so the triage is auditable; there is no root-cause analysis because this is not a vulnerability fix.

Structural signals: smartptr_member_added (+4.87), null_guard (+1.2), clamp_saturate (+1.8)